The Sweat Test

Learning how much you sweat is important in order to determine how much you need to drink while running. I weighted myself nude before a run the other day (with an empty bladder), went running for one hour without ingesting anything, and weighted myself after the run (also with an empty bladder). I had lost 2.2 pounds, which is exactly one liter! (Every pound equals 15.4 oz and there are about 34 oz in one liter). I plan on repeating this test at various temperatures and humidity levels, but for now, I’m replenishing my sweat and urine with 1 liter of liquid per hour of running. During short runs I simply take water. During the long runs, I make sure I have 7-8% carb to water solution (grams to milliliters). Interestingly, Gatorade only provides about a 5% carb to water ratio – not enough for a long run. I’m beginning to do some research on the correct amount of sodium and potassium replenishment – I’ll post on it later.